As seller here are a few reasons, my own experience.

1. Buyer can lied that they received wrong items, broken, defective, cheated on you by returning broken one and kept good one.
2. Buyer will give you negative feedback anyway they want and it will never get reversed, ebay will not do anything about it.
3. You, a seller, cannot give negative feedback nor leave negative comments even though it’s true.
4. You, seller, pay fees for posting an item even though it’s not sold, and you additional fees 10% when it sold, and another 4% to paypal and some might even pay for shipping.
5. You now have to collect tax, and report tax collected and pay to uncle Sam, it is now a requirement, must comply.
6. Once you have a couple negative feedback, your feedback % don’t look good, no one want to buy from you anymore, so better to quit.
7. Ebay basic store cost $20 a month, if you want discount, but it’s a waste of money if you don’t sell much volume monthly and still have to pay fees, in additional you would still have to pay for posting fees and final sold price fees, so it’s not completely a good discount deal.
8. The items you’re selling don’t worth all the above hassle. So quit selling stuff on ebay before it’s too late LOL.

It’s better to sell at flea market or online forum, sometime get good value on craigslist too if don’t mind face to face transactions. But I think the best is pack it up and store it, never know might need it later in the future or keep it as collectible it might have value hundreds years later for your great great grand kids LOL 🙂